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United States Patent | 5,140,580 |
Ohara ,   et al. | August 18, 1992 |
This invention relates to a method of determining the optimal recording power for an optical disk apparatus. Specifically, the apparatus, which records a signal on a recording medium through the projection of a laser beam at two levels of bias power and peak power, initially records a signal on an assessment track by decreasing the peak power progressively, with the bias power being fixed, determines the lower-limit peak power based on peak power immediately before the reproduced signal is first judged to be unsatisfactory by reproduced signal quality discrimination means, subsequently records a signal by decreasing the bias power progressively, with the peak power being fixed, determines the lower-limit bias power based on bias power immediately before the reproduced signal is first judges to be unsatisfactory by the reproduced signal quality discrimination means adds prescribed powers to the lower-limit peak power and bias power thereby to evaluate the optimal peak power and optimal bias power for the optical disk apparatus, and performs the recording of user data with the optimal peak power and optimal bias power.
Inventors: | Ohara; Shunji (Higashiosaka, JP); Moriya; Mitsuro (Ikoma, JP); Fukushima; Yoshihisa (Osaka, JP); Ishibashi; Kenzo (Moriguchi, JP) |
Assignee: | Matsushita Electric Industrial Co., Ltd. (Osaka, JP) |
Appl. No.: | 617557 |
Filed: | November 26, 1990 |
Nov 30, 1989[JP] | 1-311181 |
Current U.S. Class: | 369/53.18; 369/53.27; 369/53.36; 369/53.37; 369/106 |
Intern'l Class: | G11B 007/00 |
Field of Search: | 369/116,100,106,121,122,124,53,54,55,56,57,58,32 358/342 |
4516242 | May., 1985 | Yokota | 369/116. |
4631713 | Dec., 1986 | Romeas et al. | 369/116. |
4698797 | Oct., 1987 | Komatsu | 369/116. |
4788674 | Nov., 1988 | Maeda et al. | 369/54. |
4855988 | Aug., 1989 | Shinbayashi et al. | 369/116. |
4858219 | Aug., 1989 | Yoshikawa | 369/116. |
4907212 | Mar., 1990 | Pharris et al. | 369/54. |
4937799 | Jun., 1990 | Hashimoto et al. | 369/116. |
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